Anisotropic shear strength of a residual soil of sandstone

2008 ◽  
Vol 45 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Adriano Virgilio Damiani Bica ◽  
Luiz Antônio Bressani ◽  
Diego Vendramin ◽  
Flávia Burmeister Martins ◽  
Pedro Miguel Vaz Ferreira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Effective Stress ◽  
Yield Surface ◽  
Triaxial Compression ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Residual Soil ◽  
Compression Tests ◽  
Soil Stiffness ◽  
Particle Bonding

This paper discusses results of laboratory tests carried out with a residual soil originated from the weathering of eolian sandstone from southern Brazil. Parent rock features, like microfabric and particle bonding, are remarkably well preserved within this residual soil. Stiffness and shear strength properties were evaluated with consolidated drained (CID) and consolidated undrained (CIU) triaxial compression tests. Undisturbed specimens were tested with two different orientations between the specimen axis and bedding surfaces (i.e., parallel (δ = 0°) or perpendicular (δ = 90°)) to investigate the effect of anisotropy. When CID triaxial tests were performed with δ = 0°, the yield surface associated with the structure was much larger than when tests were performed with δ = 90°. Coincidently, CIU tests with δ = 0° showed peak shear strengths much greater than for δ = 90° at comparable test conditions. Once the peak shear strength was surpassed, CIU tests followed collapse-type effective stress paths not shown by corresponding tests with remolded specimens. A near coincidence was observed between the yield surface determined with CID tests and the envelope of collapse-type effective stress paths for δ = 0° and δ = 90°.

Prediction of Stress-Strain Response Using Rotational Multiple Yield Surface Framework in Malaysian Residual Soil

2020 ◽  
Vol 843 ◽  
pp. 132-137
Author(s):  
Asmidar Alias ◽  
Mohd Jamaludin Md Noor ◽  
Abdul Samad Abdul Rahman
Keyword(s):  
Shear Strength ◽  
Effective Stress ◽  
Volume Change ◽  
Yield Surface ◽  
Axial Strain ◽  
The Body ◽  
Residual Soil ◽  
Strain Response ◽  
Stress Strain ◽  
Soil Volume

Soil settlement is normally quantified using conventional soil volume change models which are solely based on the effective stress and the role of shear strength is ignored due to the difficulties to incorporate in the framework. The Rotational Multiple Yield Surface Framework (RMYSF) is a soil volume change model developed from the standpoint of the interaction between the effective stress and shear strength. RMYSF incorporates the development of mobilised shear strength within the body of the soil whenever the soil is subjected to anisotropic compression. Currently the framework has been applied to predict the soil anisotropic stress-strain behaviour at any effective stress. This paper present the enhancement of this volume change framework using normalisation of axial strain with the understanding that the failure axial strain is not unique, but increases as the effective stress increases. This technique has essentially produced a better accuracy in the prediction of the stress-strain response for Malaysian residual soils. A series of drained tri-axial tests under various effective stresses has been conducted using specimens of 50mm diameter and 100mm height and from the stress-strain curves the inherent mobilised shear strength envelopes at various axial strains have been determined. These mobilised shear strength envelopes were then applied for the prediction of the soil stress-strain response. An excellent agreement between the predicted and the actual stress-strain curves has been achieved.

On the Hypothesis of Effective Stress in Consolidation and Strength for Unsaturated Soils

2012 ◽  
Vol 256-259 ◽  
pp. 108-111
Author(s):  
Seboong Oh ◽  
Ki Hun Park ◽  
Oh Kyun Kwon ◽  
Woo Jung Chung ◽  
Kyung Joon Shin
Keyword(s):  
Shear Strength ◽  
Soil Water ◽  
Effective Stress ◽  
Unsaturated Soils ◽  
Water Retention Curve ◽  
Triaxial Tests ◽  
Residual Soil ◽  
Soil Behavior ◽  
Soil Water Retention Curve ◽  
Soil Water Retention

The hypothesis on effective stress of unsaturated soils is validated by consolidation strength results of triaxial tests for the compacted residual soil. The effective stress can describe the unsaturated soil behavior, which was defined from shear strength or from soil water characteristic curves. Since the effective stress from consolidation agrees with that from the shear strength, the effective stress from soil water retention curve could describe the unsaturated behavior consistently on both consolidation path and stress at failure. The effective stress can describe the entire unsaturated behavior from consolidation to failure.

Mechanical Properties of Bentonite-Sand Mixtures Under Triaxial Stress Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
M. Umedera ◽  
A. Fujiwara ◽  
N. Yasufuku ◽  
M. Hyodo ◽  
H. Murata
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Compression Tests ◽  
Optimum Water Content ◽  
Triaxial Compression Tests ◽  
Optimum Water

AbstractA series of triaxial compression tests is being conducted under the drained condition on bentonite and sand mixtures, known as buffer, in saturated and optimum water content states to clarify the mechanical properties of the buffer.It was found that the mechanical properties of bentonite and sand mixtures are strongly influenced by water and bentonite contents: shear strength in a saturated state is less than that in an optimum water content state; shear strength decreases rapidly with increasing bentonite content. Strength properties are much dependent on confining pressure.

scholarly journals Leaching Impact on Compressibility and Shear Strength of Undisturbed and Cement-treated Champlain Sea Clay

2021 ◽  
Author(s):  
Mohammad Afroz
Keyword(s):  
Shear Strength ◽  
Triaxial Compression ◽  
Strength Properties ◽  
Experimental Results ◽  
Salinity Level ◽  
Compression Tests ◽  
Treated Sample ◽  
Salinity Levels ◽  
Geotechnical Tests ◽  
The Impact

This research investigated the impact of leaching on the compressibility and shear strength properties of undisturbed and cement-treated Champlain Sea clay. A total of five undisturbed clay samples were leached with distilled water in the laboratory to reduce the salinity from initial values ranging from 9.5 to 15 g/L to the salinity values of 2.75, 1.45, 1.03, 0.55, and 0.35 g/L. A series of geotechnical tests were conducted on these samples at different salinity levels, including constant rate of strain consolidation tests, consolidated isotropic undrained triaxial compression tests, and vane shear tests. The experimental results showed that leaching leads to an increase in the compressibility and a reduction in shear strength of undisturbed Champlain Sea clay. The experimental results revealed that cement, mixed at a dosage of 50 kg/m3 , can significantly decrease the compressibility and increase the shear strength of Champlain Sea clay. A leached cement-treated sample exhibits a relatively higher compressibility than that of unleached cementtreated one. An increase in compressibility was also observed as salinity declines for the cementtreated samples. Moreover, a cement-treated sample at a lower salinity level displays slightly a higher shear strength compared to that of a cement-treated sample at the original salinity level.

Shear strength testing of intact and recompacted samples of municipal solid waste

2009 ◽  
Vol 46 (10) ◽  
pp. 1133-1145 ◽  
Author(s):  
Manoj K. Singh ◽  
Jitendra S. Sharma ◽  
Ian R. Fleming
Keyword(s):  
Shear Strength ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Effective Stress ◽  
Deformation Behaviour ◽  
Triaxial Compression ◽  
Large Diameter ◽  
Shear Behaviour ◽  
Triaxial Tests ◽  
Strength Testing

This paper presents results of shear strength testing of intact and recompacted samples of municipal solid waste (MSW). A method for in situ sampling of MSW from landfills using a push-in sampler was developed and used to obtain intact samples of MSW from a large municipal landfill. Shear strength testing of MSW was carried out using a large triaxial compression apparatus as well as a large direct shear apparatus. The results are presented in terms of cohesion intercept (c′) and angle of shearing resistance ([Formula: see text]) and are compared with those available in published literature. Based on these results and their favourable comparison with this literature, it can be concluded that meaningful shear strength parameters for MSW can be obtained using consolidated undrained triaxial tests on large-diameter intact and recompacted samples. A fairly consistent picture of the shear behaviour of MSW obtained from effective stress paths in triaxial tests appears to suggest that shear behaviour of MSW can be explained using the effective stress principle. It is suggested that recompacted samples could be used for obtaining reasonable estimates of c′ and [Formula: see text] for MSW; however, it may be necessary to use intact samples to establish the pre-failure deformation behaviour of MSW.

scholarly journals Shear strength properties of Hong Kong soils for slope stability

2020 ◽  
Vol 27 (1) ◽  
pp. 48-54
Author(s):  
Hong Yau Wong
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Slope Stability ◽  
Triaxial Compression ◽  
Quantitative Relationship ◽  
Site Investigation ◽  
Standard Penetration Test ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Soil Shear Strength

With the recent advancement in technology, the method, accuracy and speed of slope stability analysis have been vastly improved. Nevertheless, the reliability and appropriateness of such analysis can be very much in doubt if the soil behaviour, in particular the shear strength behaviour, is not fully understood. The objective of this paper is therefore to evaluate the shear strength behaviour of various soil types in Hong Kong. This comprises the collection, processing and analysis of the laboratory and field works carried out in the past few decades, in particular the triaxial compression testing in the laboratory and standard penetration test (SPT) in the field. For correlating SPT with soil shear strength, a fairly large number of carefully controlled site investigation works with SPT are carried out both above and below any Mazier sampling. Laboratory triaxial tests are then carried out in these Mazier samples. Finally, it is hoped that a basically quantitative relationship between soil shear strength and SPT can be obtained as this would enable a soil shear strength profile to be established once the corresponding SPT profile has been determined on site by carrying out SPT in adequate number of drill holes.

Specimen size effects on behavior of loose sand in triaxial compression tests

2015 ◽  
Vol 52 (6) ◽  
pp. 732-746 ◽  
Author(s):  
Tarek Omar ◽  
Abouzar Sadrekarimi
Keyword(s):  
Shear Strength ◽  
Size Effects ◽  
Scale Effects ◽  
Triaxial Compression ◽  
Shear Banding ◽  
Specimen Size ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Shear Strength Parameters ◽  
Strength Parameters

Triaxial tests are often used to determine the behavior and strength characteristics of soils without due attention to the differences in specimen size. Several drained and undrained monotonic triaxial compression shear tests are performed in this study on three different specimen sizes of the same sand to investigate the influence of specimen size and scale effect on sand compression and shear behavior. The behavior of a sand specimen is strongly influenced by shear banding and specimen boundary conditions, which are manifested as specimen size effects in the test results of this study. The measured sand compressibility and shear strength parameters are employed to describe scale effects, and investigate specimen size effects in liquefaction triggering analysis. The results show that while larger specimens exhibit a less compressible behavior during isotropic compression, larger shear strengths and effective friction angles are mobilized in the smaller specimens during shearing. A number of geotechnical analyses can be significantly affected by variations in strength parameters of the same soil determined from different specimen sizes. While using small size specimens for determining shear strength parameters might result in an unconservative design, a large specimen size provides a more accurate representation of different soil strength conditions and field deformations.

scholarly journals Leaching Impact on Compressibility and Shear Strength of Undisturbed and Cement-treated Champlain Sea Clay

2021 ◽  
Author(s):  
Mohammad Afroz
Keyword(s):  
Shear Strength ◽  
Triaxial Compression ◽  
Strength Properties ◽  
Experimental Results ◽  
Salinity Level ◽  
Compression Tests ◽  
Treated Sample ◽  
Salinity Levels ◽  
Geotechnical Tests ◽  
The Impact

This research investigated the impact of leaching on the compressibility and shear strength properties of undisturbed and cement-treated Champlain Sea clay. A total of five undisturbed clay samples were leached with distilled water in the laboratory to reduce the salinity from initial values ranging from 9.5 to 15 g/L to the salinity values of 2.75, 1.45, 1.03, 0.55, and 0.35 g/L. A series of geotechnical tests were conducted on these samples at different salinity levels, including constant rate of strain consolidation tests, consolidated isotropic undrained triaxial compression tests, and vane shear tests. The experimental results showed that leaching leads to an increase in the compressibility and a reduction in shear strength of undisturbed Champlain Sea clay. The experimental results revealed that cement, mixed at a dosage of 50 kg/m3 , can significantly decrease the compressibility and increase the shear strength of Champlain Sea clay. A leached cement-treated sample exhibits a relatively higher compressibility than that of unleached cementtreated one. An increase in compressibility was also observed as salinity declines for the cementtreated samples. Moreover, a cement-treated sample at a lower salinity level displays slightly a higher shear strength compared to that of a cement-treated sample at the original salinity level.

Strength envelope of granular soil stabilized by multi-axial geogrid in large triaxial tests

2020 ◽  
Vol 57 (3) ◽  
pp. 448-452 ◽  
Author(s):  
A.S. Lees ◽  
J. Clausen
Keyword(s):  
Triaxial Compression ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Failure Envelope ◽  
Element Analysis ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Triaxial Compression Tests ◽  
Properties Of Soil

Conventional methods of characterizing the mechanical properties of soil and geogrid separately are not suited to multi-axial stabilizing geogrid that depends critically on the interaction between soil particles and geogrid. This has been overcome by testing the soil and geogrid product together as one composite material in large specimen triaxial compression tests and fitting a nonlinear failure envelope to the peak failure states. As such, the performance of stabilizing, multi-axial geogrid can be characterized in a measurable way. The failure envelope was adopted in a linear elastic – perfectly plastic constitutive model and implemented into finite element analysis, incorporating a linear variation of enhanced strength with distance from the geogrid plane. This was shown to produce reasonably accurate simulations of triaxial compression tests of both stabilized and nonstabilized specimens at all the confining stresses tested with one set of input parameters for the failure envelope and its variation with distance from the geogrid plane.

Sign in / Sign up

Export Citation Format

Share Document